CTO說了，如果發(fā)現(xiàn)誰用kill -9關(guān)閉程序就開除

kill可將指定的信息送至程序。預(yù)設(shè)的信息為SIGTERM(15)，可將指定程序終止。若仍無法終止該程序，可使用SIGKILL(9)信息嘗試強(qiáng)制刪除程序。程序或工作的編號可利用ps指令或jobs指令查看（這段話來自菜鳥教程）。

講的這個復(fù)雜，簡單點(diǎn)來說就是用來殺死linux中的進(jìn)程，啥？你問我啥是進(jìn)程？請自行百度。

我相信很多人都用過kill -9 pid 這個命令，徹底殺死進(jìn)程的意思，一般情況我們使用它沒有上面問題，但是在我們項(xiàng)目中使用它就有可能存在致命的問題。

kill -9 pid 帶來的問題

由于kill -9 屬于暴力刪除，所以會給程序帶來比較嚴(yán)重的后果，那究竟會帶來什么后果呢？

舉個栗子：轉(zhuǎn)賬功能，再給兩個賬戶進(jìn)行加錢扣錢的時(shí)候突然斷電了？這個時(shí)候會發(fā)生什么事情？對于InnoDB存儲引擎來說，沒有什么損失，因?yàn)樗С质聞?wù)，但是對于MyISAM引擎來說那簡直就是災(zāi)難，為什么？假如給A賬戶扣了錢，現(xiàn)在需要將B賬戶加錢，這個時(shí)候停電了，就會造成，A的錢被扣了，但是B沒有拿到這筆錢，這在生產(chǎn)環(huán)境是絕對不允許的，kill -9 相當(dāng)于突然斷電的效果。

當(dāng)然了，像轉(zhuǎn)賬這種，肯定不是使用MyISAM引擎，但是如今分布式火了起來，跨服務(wù)轉(zhuǎn)賬已經(jīng)是很平常的事情，這種時(shí)候如果使用kill -9 去停止服務(wù)，那就不是你的事務(wù)能保證數(shù)據(jù)的準(zhǔn)確性了，這個時(shí)候你可能會想到分布式事務(wù)，這個世界上沒有絕對的安全系統(tǒng)或者架構(gòu)，分布式事務(wù)也是一樣，他也會存在問題，概率很小，如果一旦發(fā)生，損失有可能是無法彌補(bǔ)的，所以一定不能使用kill -9 去停止服務(wù)，因?yàn)槟悴恢浪麜斐墒裁春蠊?/p>

在MyISAM引擎中表現(xiàn)的更明顯，比如用戶的信息由兩張表維護(hù)，管理員修改用戶信息的時(shí)候需要修改兩張表，但由于你的kill -9 暴力結(jié)束項(xiàng)目，導(dǎo)致只修改成功了一張表，這也會導(dǎo)致數(shù)據(jù)的不一致性，這是小事，因?yàn)榇蟛涣嗽傩薷囊淮?，但是金錢、合同這些重要的信息如果由于你的暴力刪除導(dǎo)致錯亂，我覺得可能比刪庫跑路還嚴(yán)重，至少刪庫還能恢復(fù)，你這個都不知道錯在哪里。

那我們應(yīng)該怎么結(jié)束項(xiàng)目呢？

其實(shí)java給我們提供了結(jié)束項(xiàng)目的功能，比如：tomcat可以使用shutdown.bat/shutdown.sh進(jìn)行優(yōu)雅結(jié)束。

什么叫優(yōu)雅結(jié)束？

“

第一步：停止接收請求和內(nèi)部線程。第二步：判斷是否有線程正在執(zhí)行。第三步：等待正在執(zhí)行的線程執(zhí)行完畢。第四步：停止容器。

”

以上四步才是正常的結(jié)束流程，那springboot怎么正常結(jié)束服務(wù)呢？下面我介紹幾種正常結(jié)束服務(wù)的方案，請拿好小本本做好筆記。

優(yōu)雅結(jié)束服務(wù)

kill -15 pid

這種方式也會比較優(yōu)雅的結(jié)束進(jìn)程（項(xiàng)目），使用他的時(shí)候需要慎重，為什么呢？我們來看個例子

我寫了一個普通的controller方法做測試

@GetMapping(value?=?"/test")
????public?String?test(){
????????log.info("test?---?start");
????????try?{
????????????Thread.sleep(100000);
????????}?catch?(InterruptedException?e)?{
????????????e.printStackTrace();
????????}
????????log.info("test?---?end");
????????return?"test";
????}
1234567891011

代碼很簡單，打?。簍est — start之后讓讓程序休眠100秒，然后再打?。簍est — end，在線程休眠中我們使用kill -15 pid來結(jié)束這個進(jìn)程，你們猜 test — end會被打印嗎？

application.yml

server:
??port:?9988
12

啟動項(xiàng)目

sudo mvn spring-boot:run
1

這是maven啟動springboot項(xiàng)目的方式看到這個就代表項(xiàng)目啟動成了

找到項(xiàng)目的進(jìn)程id

sudo ps -ef |grep shutdown
1

這個就是項(xiàng)目的進(jìn)程號，接下來我們先測試test接口，讓線程進(jìn)入休眠狀態(tài)，然后再使用kill -15 14086停止項(xiàng)目

sudo curl 127.0.0.1:9988/test
1

回到項(xiàng)目日志我們發(fā)現(xiàn)請求已經(jīng)到達(dá)服務(wù)，并且線程已經(jīng)成功進(jìn)入休眠，現(xiàn)在我們kill -15 14086結(jié)束進(jìn)程

sudo kill -15 14086
1

回到日志

2020-04-24?10:53:14.939??INFO?14086?---?[nio-9988-exec-1]?com.ymy.controller.TestController????????:?test?---?start
2020-04-24?10:54:02.450??INFO?14086?---?[extShutdownHook]?o.s.s.concurrent.ThreadPoolTaskExecutor??:?Shutting?down?ExecutorService?'applicationTaskExecutor'
java.lang.InterruptedException:?sleep?interrupted
?at?java.lang.Thread.sleep(Native?Method)
?at?com.ymy.controller.TestController.test(TestController.java:26)
?at?sun.reflect.NativeMethodAccessorImpl.invoke0(Native?Method)
?at?sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
?at?sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
?at?java.lang.reflect.Method.invoke(Method.java:498)
?at?org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
?at?org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
?at?org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)
?at?org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879)
?at?org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
?at?org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
?at?org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
?at?org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
?at?org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
?at?org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
?at?javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
?at?org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
?at?javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
?at?org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
?at?org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
?at?org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
?at?org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109)
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
?at?org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
?at?org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
?at?org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
?at?org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
?at?org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
?at?org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
?at?org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
?at?org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
?at?org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)
?at?org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
?at?org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
?at?org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594)
?at?org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
?at?java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
?at?java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
?at?org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
?at?java.lang.Thread.run(Thread.java:748)
2020-04-24?10:54:04.574??INFO?14086?---?[nio-9988-exec-1]?com.ymy.controller.TestController????????:?test?---?end
2020-04-24?10:54:04.610?ERROR?14086?---?[nio-9988-exec-1]?o.s.web.servlet.HandlerExecutionChain????:?HandlerInterceptor.afterCompletion?threw?exception

java.lang.NullPointerException:?null
?at?org.springframework.boot.actuate.metrics.web.servlet.LongTaskTimingHandlerInterceptor.stopLongTaskTimers(LongTaskTimingHandlerInterceptor.java:123)?~[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE]
?at?org.springframework.boot.actuate.metrics.web.servlet.LongTaskTimingHandlerInterceptor.afterCompletion(LongTaskTimingHandlerInterceptor.java:79)?~[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE]
?at?org.springframework.web.servlet.HandlerExecutionChain.triggerAfterCompletion(HandlerExecutionChain.java:179)?~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletion(DispatcherServlet.java:1427)?[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1060)?[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)?[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)?[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)?[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?javax.servlet.http.HttpServlet.service(HttpServlet.java:634)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)?[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?javax.servlet.http.HttpServlet.service(HttpServlet.java:741)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)?[tomcat-embed-websocket-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109)?[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE]
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)?[spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE]
?at?org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)?[na:1.8.0_242]
?at?java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)?[na:1.8.0_242]
?at?org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)?[tomcat-embed-core-9.0.33.jar:9.0.33]
?at?java.lang.Thread.run(Thread.java:748)?[na:1.8.0_242]

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112

居然報(bào)錯了，但是test — end是打印出來了，為什么會報(bào)錯呢？這就和sleep這個方法有關(guān)了，在線程休眠期間，當(dāng)調(diào)用線程的interrupt方法的時(shí)候會導(dǎo)致sleep拋出異常，這里很明顯就是kill -15 這個命令會讓程序馬上調(diào)用線程的interrupt方法，目的是為了讓線程停止，雖然讓線程停止，但線程什么時(shí)候停止還是線程自己說的算，這就是為什么我們還能看到：test — end的原因。更多的 Spring Boot 視頻教程可以關(guān)注微信訂閱號碼匠筆記回復(fù) Spring Boot 獲取。

ConfigurableApplicationContext colse

我們先看怎么實(shí)現(xiàn)

package?com.ymy.controller;

import?lombok.extern.slf4j.Slf4j;
import?org.springframework.beans.BeansException;
import?org.springframework.context.ApplicationContext;
import?org.springframework.context.ApplicationContextAware;
import?org.springframework.context.ConfigurableApplicationContext;
import?org.springframework.web.bind.annotation.GetMapping;
import?org.springframework.web.bind.annotation.PostMapping;
import?org.springframework.web.bind.annotation.RestController;

@RestController
@Slf4j
public?class?TestController??implements?ApplicationContextAware?{

????private??ApplicationContext??context;

????@Override
????public?void?setApplicationContext(ApplicationContext?applicationContext)?throws?BeansException?{
????????this.context?=?applicationContext;
????}


????@GetMapping(value?=?"/test")
????public?String?test(){
????????log.info("test?---?start");
????????try?{
????????????Thread.sleep(100000);
????????}?catch?(InterruptedException?e)?{
????????????e.printStackTrace();
????????}
????????log.info("test?---?end");
????????return?"test";
????}

????/**
?????*?停機(jī)
?????*/
????@PostMapping(value?=?"shutdown")
????public?void?shutdown(){
????????ConfigurableApplicationContext?cyx?=?(ConfigurableApplicationContext)?context;
????????cyx.close();
????}
}
1234567891011121314151617181920212223242526272829303132333435363738394041424344

重點(diǎn)在：cyx.close();，為什么他能停止springboot項(xiàng)目呢？請看源碼

public?void?close()?{
????????synchronized(this.startupShutdownMonitor)?{
????????????this.doClose();
????????????if?(this.shutdownHook?!=?null)?{
????????????????try?{
????????????????????Runtime.getRuntime().removeShutdownHook(this.shutdownHook);
????????????????}?catch?(IllegalStateException?var4)?{
????????????????}
????????????}

????????}
????}
123456789101112

程序在啟動的時(shí)候向jvm注冊了一個關(guān)閉鉤子，我們在執(zhí)行colse方法的時(shí)候會刪除這個關(guān)閉鉤子，jvm就會知道這是需要停止服務(wù)。

我們看測試結(jié)果很明顯，他也出發(fā)了線程的interrupt方法導(dǎo)致線程報(bào)錯，原理和kill -15差不多。

actuator

這種方式是通過引入依賴的方式停止服務(wù)，actuator提供了很多接口，比如健康檢查，基本信息等等，我們也可以使用他來優(yōu)雅的停機(jī)。

引入依賴

????????????org.springframework.boot
????????????spring-boot-starter-actuator
????????

12345

application.yml

server:
??port:?9988

management:
??endpoints:
????web:
??????exposure:
????????include:?shutdown
??endpoint:
????shutdown:
??????enabled:?true
??server:
????port:?8888
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我這里對actuator的接口重新給定了一個接口，這樣可提高安全性，下面我們來測試一下

@RequestMapping(value?=?"/test",method?=?RequestMethod.GET)
????public?String?test(){
????????System.out.println("test?---?start");
????????try?{
????????????Thread.sleep(10000);
????????}?catch?(InterruptedException?e)?{
????????????e.printStackTrace();
????????}
????????System.out.println("test?---?end");
????????return?"hello";
????}
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在請求test途中停止服務(wù)我們發(fā)現(xiàn)發(fā)送停止服務(wù)請求之后還給我們返回了提示信息，很人性化，我們看看控制臺test — end被執(zhí)行了，不過在停止線程池的時(shí)候還是調(diào)用了線程的interrupt方法，導(dǎo)致sleep報(bào)錯，這三種方式都可以比較優(yōu)雅的停止springboot服務(wù)，如果我項(xiàng)目中存在線程休眠，我希望10秒以后再停止服務(wù)可以嗎？肯定是可以的，我們只需要稍微做點(diǎn)修改就可以了。

1.新增停止springboot服務(wù)類：ElegantShutdownConfig.java

package?com.ymy.config;

import?org.apache.catalina.connector.Connector;
import?org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;
import?org.springframework.context.ApplicationListener;
import?org.springframework.context.event.ContextClosedEvent;

import?java.util.concurrent.Executor;
import?java.util.concurrent.ThreadPoolExecutor;
import?java.util.concurrent.TimeUnit;

public?class?ElegantShutdownConfig?implements?TomcatConnectorCustomizer,?ApplicationListener<ContextClosedEvent>?{

????private?volatile?Connector?connector;
????private?final?int?waitTime?=?10;

????@Override
????public?void?customize(Connector?connector)?{
????????this.connector?=?connector;
????}

????@Override
????public?void?onApplicationEvent(ContextClosedEvent?event)?{
????????connector.pause();
????????Executor?executor?=?connector.getProtocolHandler().getExecutor();
????????if?(executor?instanceof?ThreadPoolExecutor)?{
????????????try?{
????????????????ThreadPoolExecutor?threadPoolExecutor?=?(ThreadPoolExecutor)?executor;
????????????????threadPoolExecutor.shutdown();
????????????????if?(!threadPoolExecutor.awaitTermination(waitTime,?TimeUnit.SECONDS))?{
????????????????????System.out.println("請嘗試暴力關(guān)閉");
????????????????}
????????????}?catch?(InterruptedException?ex)?{
????????????????System.out.println("異常了");
????????????????Thread.currentThread().interrupt();
????????????}
????????}

????}
}

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2.在啟動類中加入bean

package?com.ymy;

import?com.ymy.config.ElegantShutdownConfig;
import?lombok.extern.slf4j.Slf4j;
import?org.apache.catalina.connector.Connector;
import?org.springframework.boot.SpringApplication;
import?org.springframework.boot.autoconfigure.SpringBootApplication;
import?org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer;
import?org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory;
import?org.springframework.boot.web.servlet.server.ServletWebServerFactory;
import?org.springframework.context.ApplicationListener;
import?org.springframework.context.ConfigurableApplicationContext;
import?org.springframework.context.annotation.Bean;
import?org.springframework.context.event.ContextClosedEvent;

import?java.util.concurrent.Executor;
import?java.util.concurrent.ThreadPoolExecutor;
import?java.util.concurrent.TimeUnit;

@SpringBootApplication
public?class?ShutdownServerApplication?{

????public?static?void?main(String[]?args)?{
????????ConfigurableApplicationContext?run?=?SpringApplication.run(ShutdownServerApplication.class,?args);
????????run.registerShutdownHook();
????}


????@Bean
????public?ElegantShutdownConfig?elegantShutdownConfig()?{
????????return?new?ElegantShutdownConfig();
????}

????@Bean
????public?ServletWebServerFactory?servletContainer()?{
????????TomcatServletWebServerFactory?tomcat?=?new?TomcatServletWebServerFactory();
????????tomcat.addConnectorCustomizers(elegantShutdownConfig());
????????return?tomcat;
????}
}

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這樣我們就配置好了，我們再來測試一遍，test的接口還是休眠10秒我們發(fā)現(xiàn)這次沒有報(bào)錯了，他是等待了一段時(shí)間之后再結(jié)束的線程池，這個時(shí)間就是我們在ElegantShutdownConfig類中配置的waitTime。

那可能你會有疑問了，jvm沒有立即停止，那這個時(shí)候在有請求會發(fā)生什么呢？如果關(guān)閉的時(shí)候有新的請求，服務(wù)將不在接收此請求。

數(shù)據(jù)備份操作

如果我想在服務(wù)停止的時(shí)候做點(diǎn)備份操作啥的，應(yīng)該怎么做呢？其實(shí)很簡單在你要執(zhí)行的方法上添加一個注解即可：@PreDestroy

“

Destroy：消滅、毀滅 pre:前綴縮寫

”

所以合在一起的意思就是在容器停止之前執(zhí)行一次，你可以在這里面做備份操作，也可以做記錄停機(jī)時(shí)間等。

新增服務(wù)停止備份工具類：DataBackupConfig.java

package?com.ymy.config;

import?org.springframework.context.annotation.Configuration;

import?javax.annotation.PreDestroy;

@Configuration
public?class?DataBackupConfig?{

????@PreDestroy
????public??void?backData(){

????????System.out.println("正在備份數(shù)據(jù)。。。。。。。。。。。");
????}
}
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我們再來測試然后打印控制臺日志：

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